Family: Asteraceae
High Risk Traits:
- Broad climate suitability, and elevation range exceeds 1000 m, demonstrating environmental versatility
- Naturalized in regions with tropical climates
- Naturalized on Oahu, Lanai, and Hawaii (Hawaiian Islands) as well as North America and Australia
- A weed of disturbed areas and certain crops
- Other Arctium species are invasive
- Pointed, barbed bracts may harm eyes of animals, or tongues of dogs grooming themselves with the burrs stuck in their fur
- Host of crop pathogens
- Shade tolerant
- Tolerates many soil types
- Reproduces by seeds, and may be able to regenerate from large, tuberous root
- Hybridizes with other Arctium species
- Reaches maturity in two years (biennial)
- Hooked outer phyllaries (bracts) facilitate animal (including human) dispersal of the heads. Heads may also be transported by water
- Seeds also dispersed as a produce contaminant
- Seeds may form a persistent seed bank (21+ years)
- May be able to resprout from roots if not completely removed
Low Risk Traits:
- A domesticated plant, long cultivated as a food crop. Harvesting prior to flowering minimizes risk of invasiveness
- Palatable to deer, and possibly other browsing animals, but burrs may deter browsing
- Herbicides may provide effective control
